question

cflenker avatar image
cflenker asked

CVL of DVCC does not work

We are operating 5 quite similar victron 3phase systems with ac-out connected pv-inverters and diy lf280k battery packs with serialbattery-driver.

The serialbattery-driver reduces CVL (charge voltage limitation) if a single cell rises above 3.46v to prevent overcharging of this single cell and give time to the active balancer (jkbms).

This works fine for 4 of the 5 systems.

But the 5th systems seem not to obey CVL especially when we have high pv-Power (i don't understand this dependancy - grid is on and the pv-power can be fed into the grid).

1713839057452.png

I checked all settings and compared them to the other 4 systems that work fine.

The only difference I can see is the way the serialnummer of the multiplus are displayed in the remote console:

Here the system that does not work:

1713839345452.png

1713839385268.png

For the other 4 good working systems only the present devices are shown:

1713839511194.png

Does anyone have an idea?

Every advice is very much appreciated!

Multiplus-IIDVCCserialbatterycvl
1713839057452.png (64.8 KiB)
1713839345452.png (20.0 KiB)
1713839385268.png (18.8 KiB)
1713839511194.png (17.8 KiB)
11 comments
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

nickdb avatar image nickdb ♦♦ commented ·
Same Cerbo versions and firmware?

The serial driver is unsupported, so if the obvious is eliminated then, this is better off moved to modifications section.

0 Likes 0 ·
Alexandra avatar image Alexandra ♦ nickdb ♦♦ commented ·

In commissioning was there any differences noted on the ve bus dc measurements?

0 Likes 0 ·
cflenker avatar image cflenker Alexandra ♦ commented ·

All DC voltage measurements are quite the same (VE-Bus, SmartShunt, SerialBatteryDriver) and all are far above CVL.

0 Likes 0 ·
cflenker avatar image cflenker nickdb ♦♦ commented ·
Thank you for moving to the correct chapter.

Cerbo-S GX is on the newest Version V3.30.

On the other systems we use Cerbo GX (without -S) but same Firmware Version V3.30.

May this be the Problem? I think Cerbo-S GS should work as well. Don't you think so?

0 Likes 0 ·
nickdb avatar image nickdb ♦♦ cflenker commented ·
Identical OS, that won’t contribute.
0 Likes 0 ·
Al avatar image Al commented ·
I guess you only have one BMS for each installation, so you don't need battery aggregator? The Pulquero aggregator needs an edit to the config. JSON to allow serial battery CVL limitation to work as expected.
0 Likes 0 ·
cflenker avatar image cflenker Al commented ·

Hello @Al, thanks for your hint. In this installation we only use one battery-pack and only one BMS. I can only measure the CVL that comes out of the serialbattery-driver. This CVL is correct. It would be interesting to measure the CVL on the VE.Bus to the Multis. But I don't have an idea how to do this. Is there a way to do this?

0 Likes 0 ·
Al avatar image Al cflenker commented ·

I'm not sure as I've not checked myself when CVL is limiting, but if you look on dbus-spy at your BMS (Serialbattery JKBMS) and Info/MaxChargeVoltage when you hope to see limiting, does it reduce? If it does, is it also the same for the system: Control/EffectiveChargeVoltage? I assume it should pass on the CVL voltage to System.

You could install batteryaggregator then you could see on the remote console the aggregator in device list and parameters tab will show the called for CVL. < but that's maybe a lot of hassle to install everything and set up just to check.

0 Likes 0 ·
cflenker avatar image cflenker Al commented ·
Thanks @Al, that's a good idea. I will try with MQTT Explorer. I think the dbus is being mappt to MQTT. That's the easiest way for the first step. If that doesn't take me further, i will have to use dbus-spy. But I am not familiar with that yet.

Thanks a lot!

0 Likes 0 ·
Al avatar image Al cflenker commented ·

I'm not familiar with MQTT, but If you have terminal access with putty or similar it's quite easy. just type: dbus-spy in the command line, then use arrow keys to navigate. Ctrl+C to Exit.

1 Like 1 ·
cflenker avatar image cflenker cflenker commented ·

Here are the dbus values (measured via MQTT).
The system that works fine:
1713899625708.png

The system that has the problem:
1713899729917.png

(I had to calibrate VOLTAGE_DROP with 0.05v in the first application and 0.15v in the second application).

The values seem to be correct.

I will have to monitor this when the problem occurs. Let's wait for better weather.

1 Like 1 ·
1713899625708.png (9.5 KiB)
0 Answers